Tektronix 2445 User manual

Tektronix, Jne.
P.O. Box 500
Beaverton, Oregon 97077
070·4633-00
Product Group 38
COMMITTED TO EXCELLENCE
PLEASE CHECK FOR CHANGE INFORMATION
AT THE REAR OF THIS MANUAL.
2445/2465
OPTION 10
GPIB OPTION
OPERATORS
INSTRUCTION MANUAL
Serial Number ____ _
First Printing SEP 1983
Revised APR 1985

Copyright ® 1983 Tektronix, Inc. All rights reserved.
Contents of this publication may not be reproduced in any
form without the written permission of Tektronix, Inc.
Products of Tektronix. Inc. and its subsidiaries are covered
by U.S. and foreign patents and/or pending patents.
TEKTRONIX, TEK, SCOPE-MOBILE, and i! are
registered trademarks of Tektronix, Inc. TELEQUIPMENT
is a registered trademark of Tektronix U.K. Limited.
Printed
in U.S.A. Specification and price change privileges
are reserved.
INSTRUMENT SERIAL NUMBERS
Each instrument has a serial number on Ii panel insert, tag.
or stamped on the chassis. The first number or letter
deSignates the country
of manufacture. The last five digits
of the serial number are assigned sequentially and are
unique to each instrument. Those manufactured
in the
United States have six unique digits. The country of
manufacture is identified as follows:
BOOOOOO
100000
200000
300000
700000
Tektronix, Inc., Beaverton, Oregon, USA
Tektronix Guernsey. Ltd., Channel Islands
Tektronix United Kingdom, Ltd., london
Sony/Tektronix, Japan
Tektronix Holland, NV, Heerenveen,
The Netherlands

2445/2465 Option 10 Operators
TABLE OF CONTENTS
Page
LIST OF ILLUSTRATIONS .................... ii
LIST OF TABLES ........................... ii
OPERATORS SAFETY SUMMARY ............. iii
SECTION 1 SPECIFICATION
INTRODUCTION. . . . . . . . . . . . . . . .
.. 1-1
STANDARD ACCESSORIES ........ 1-1
STANDARD FUNCTIONS, FORMATS,
AND FEATURES. . . . . . . . . . . . . . . . .. 1-1
PERFORMANCE CONDITIONS ...... 1-2
SECTION 2 CONTROLS. CONNECTORS, AND
INDICATORS
FRONT-PANEL CONTROLS
....... , 2-1
REAR PANEL . . . . . . . . . . . . . . . . . . .. 2-1
INDICATORS. . . . . . . . . . . . . . • . . . • .. 2·1
READOUT DISPLAYS ............. 2-2
SECTION 3 GPIB PREPARATION FOR USE
POWER-UP SEQUENCE . . . . . . . . .
.. 3-1
Kernel Tests . . . . . . . . . . . . . . . . . .. 3-1
Confidence Test . . . . . . . . . . . . . . .. 3-1
Successful Power·Up Sequencing.. 3-1
Unsuccessful Power-Up Sequencing 3-1
POWER-DOWN SEQUENCE . . . . . . .. 3-1
SECTION 4 CONTROLLING OSCILLOSCOPE
FUNCTIONS OVER·THE GPIB
INTRODUCTION
.................. 4-1
GPIB PARAMETER SELECTION. . . .. 4-1
Primary Address. . . . . . . . . . . . . . .. 4-1
Input End-of-Message Terminator
and Talk/Usten Mode. . . . . . . . . . .. 4-1
MESSAGES AND COMMUNICATION
PROTOCOL ...... . . . . . . . . . . . . . .. 4-2
Commands . . . . . . . . . . . . . . . . . .
.. 4-2
Headers .. . . . . . . . . . . . . . . . . . . .. 4-2
Arguments .. .. . .. . .. . . . .. . .. .. 4-2
Command Separator . . . . . . . . . . .. 4-3
Message Terminator. . . . . . . . . . . .. 4-3
Command Formatting. . . . . . . . . .
.. 4-3
Numeric Arguments . . . . . . . . . . .
.. 4-3
GPIB COMMAND LISTS . . . . . . . . . .. 4-4
SECTION 4 CONTROLLING OSCILLOSCOPE
FUNCTIONS OVER THE GPIB (cont)
REMOTE-LOCAL OPERATING
Page
STATES ......................... 4-13
Local State (LOCS) ... . . . . . . . . .. 4-13
Local With Lockout State (LWLS) .. 4-13
Remote State (REMS) . . . . . . . . . .. 4-13
Remote With Lockout State (RWLS) 4-14
INSTRUMENT RESPONSE TO
INTERFACE MESSAGES ........... 4-14
Local Lockout(LLO)
............. 4-14
Remote Enable (REN) .•......... , 4-14
Go To Local (GTL) . . . . . . . . . . . . .. 4-14
My Usten and My Talk Addresses
(MLA AND MTA)
................ 4-14
Unlisten and Untalk (UNL and UNT) 4-14
Interface Clear (IFC) ............. 4-14
Device Clear (DCL) . . . . . . . . . . . .
.. 4-14
Selected Device Clear (SDC) . . . . .. 4-14
Serial Poll Enable and Disable
(SPE AND SPD) . . . . . . . . . . . . . . .. 4-14
PROGRAMMING ................. 4-15
Command Handler . . . . . . . . . . . . .. 4-15
Service-Request Handler . . . . . . .
.. 4-15
Sample Program A . . . . . . . . . . . . .. 4-15
Sample Program B . . . . . . . . . . . . .. 4-16
Using SETtings? and LLSet? Queries 4-17
Sample Program
C. . . . . . . . . . . . .. 4-17
Sample Program D. . . . . . . . . . . . .. 4-18
Front Panel Lockout. . . . . . . . . . .
.. 4-18
Reset Under GPIB Control ........ 4-19
APPENDIX A GPIB COMMAND REFERENCE .... A-1
APPENDIX B STATUS AND ERROR REPORTING B-1
APPENDIX C MESSAGE COMMAND CHARACTER
TRANSLATIONS..... ........... C-1
APPENDIX D SWEEP SPEED COMMAND
CONSIDERATIONS ............... D-1
APPENDIX E LLMESSAGE COMMAND
CHARACTER TRANSLATIONS E-1
CHANGE INFORMATION

2445/2465 Option 10 Operators
LIST OF ILLUSTRATIONS
Figure Page
The 2445 Option 10 Oscilloscope ..................... , , .... , , , .... , , , , , . , .. , , . .. iv
The 2465 Option 10 Oscilloscope . , ,
.... , ..... , . , , ........ , , ............. , , , ... ,. iv
2-1 Rear-Panel GPIB CONNECTOR, ........... , ... , .. "., .............. ,", ....... 2-1
2-2 GPIB STATUS indicators ,. , . , ... , . , . , , , ... , , ............. , . , ... , .. , . . .. . .. ,.,. 2-2
LIST OF TABLES
Table Page
1-1 ANSI/IEEE Std 488-1978 (GPIB) Functions . .................................... 1-2
1-2 Specific Features Implemented ................................................ 1-2
1-3 Specific Format Choices ..................................................... 1-2
1-4 Option 10 Electrical Characteristics
............................................ 1-3
1-5 Option 1
0 Mechanical Characteristics .......................................... 1-3
4-1 Numeric Argument Format for GPIB Commands .................................. 4-3
4-2 Vertical Commands ......................................................... 4-4
4-3 Horizontal Commands ...................................................... , 4-6
4-4 Trigger Commands ........................... ............................. 4-7
4-5 Delay and Delta Commands .................................................. 4-9
4-6 System Commands ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4-10
4-7 Calibration and Diagnostic Commands ........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4-12
A-1 GPIB Command Summary ................................................... A-1
B-1 Status Event and Error Categories ............................................ , B-1
B-2 GPIB Status Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-2
C-1 Message Command Character Translations ..................................... " C-1
0-1 Horizontal Command Results ................................................. 0-1
E-1 LLMessage? Query Character Set (Code Sequenced) ............................. E-1
E-2 LLMessage Command Character Set (Character Sequenced) ....................... E-4
ii
REV JUL 1984

2445/2465 Option 10 Operators
OPERATORS SAFETY SUMMARY
The general safety summaryin this part of the summary is for both operating and servicing personnel. Specific warnings and
cautions will be found throughout the manual where they apply anddo not appear in this summary.
Terms in This Manual
CAUTION statements identify conditions or practices that
could result in damage
to the eql,lipment or other property.
WARNING statements identify conditions or practices that
could result in personal injury
or loss of life.
Terms as Marked on Equipment
CAUTION indicates a personal injury hazard not immedi-
ately accessible as one reads the markings, or a hazard to
property, including the equipment itself.
DANGER indicates a personal injury hazard immediately ac-
cessible as one reads the marking.
Symbols as Marked on Equipment
This symbol indiCates where applicable
cautionary or other information is to be found.
Protective ground (earth) terminal.
ATTENTION -Refer
to manual.
Power Source
This product is intended to operate from a power source
that does not apply more than 250 volts rms between the
supply conductors or between either supply conductor and
ground. A protective ground connection by way of the
grounding conductor in the pow~r cord is essential for safe
operation.
Grounding the Product
This product is grounded through the grounding conductor
of the power cord. To avoid electrical shock, plug the power
cord into a properly wired receptacle before connecting
to
the product input or output terminals. A protective ground
connection by way
of the grounding conductor in the power
cord is essential for safe operation.
Danger Arising From Loss of Ground
Upon loss of the protective-ground connection, all accessi·
ble conductive parts (including knobs and controls that may
appear
to be insulating) can render an electric Shock.
Use the Proper Power Cord
Use only the power cord and connector speCified for your
product.
Use only a power cord
that is in good condition.
Use the Proper Fuse
To avoid fire hazard, use only a fuse of the correct type,
voltage rating and current rating as specified in the parts list
for your product.
Do Not Operate in Explosive Atmospheres
To avoid explosion, do not operate this product in an explo-
sive atmosphere unless it has been specifically certified for
such operation.
Do Not Remove Covers or Panels
To avoid persona! injury, do not remove the product covers
or panels. Do not operate product without the covers and
panels properly installed.
iii

2445/2465 Option 10 Operators
4633{)1
The 2446 Option 10 {GPIBI Oscilloscope.
4633-02
The 2465 Option 10 (GPIB) Oscilloscope.
iv

Section 1
2445/2465 Option 10 Operators
SPECIFICATION
INTRODUCTION
Option 10 to the TEKTRONIX 2445 and 2465 Oscillo-
scopes adds the hardware and the software that allows
these instruments to be remotely'controlled and queried us-
ing a standard interface system.
'the interface implemented
conforms
to the specifications contained in IEEE Standard
Digital Interface for Programmable instrumentation
(ANSI/IEEE Std 488-1978). commonly referred to as the
General Purpose Interface Bus (GPIB). It also complies with
a Tektronix Standard relating
to GPIB Codes. Formats,
Conventions and Features.
This manual describes GPIB operational elements only in
relation to communication between the oscilloscope and the
remote controller
by way of the bus. For complete informa-
tion regarding GPIB electrical, mechanical, and functional
aspects, refer
to ANSI/IEEE Std 488-1978, which is pub-
lished by:
The Institute of Electrical and Electronics Engineers, Inc.
345 East 47th Street .
New York, New York 10017
Messages originating from a remote controlling device
and transmitted over the GPIf3 perform one of three
functions:
1. Set the oscilloscope operating mode;
2. Query the
state of the oscilloscope; or
3. Query the results of measurements made.
All oscilloscope front-panel functions are controllable
through the GPIB interface, except the power and display
controls (INTENSITY, BEAM FINO, FOCUS, READOUT IN-
TENSITY, TRACE ROTATION,
A~TIG, SCALE ILLUM, and
POWER). Structure and format of the commands and que-
ries executable by the GPIB Option are explained in Section
4, 'Controlling Oscilloscope Functions over the GPIB". A
listing of command headers and arguments, along with con-
cise descriptions, is also provided in Section 4.
REV APR 1985
The alphanumeric crt readout is used to display mea-
surement results, diagnostknest messages, exercise mes-
sages, and calibration messages. Any measurement result
that is displayed on the crt readout can also be transmitted
over the GPIB. While the READOUT INTENSITY control it-
self is not GPIB controllable, scale-factor readouts can be
turned on and off over the bus.
STANDARD ACCESSORIES
In addition to the standard accessories listed in the basic
oscillOSCOpe manuals, one copy each of the following
Option 10 accessories is also provided:
Description
2445/2465 Option 10 Operators Manual
2445/2465 Option 10 Service Manual
2445/2465 Option 10 Reference Guide
Part
Number
070-4633-00
070-4640-00
070-5364-00
STANDARD FUNCTIONS, FORMATS,
AND FEATURES
Thetotal interface-function repertOire of an instrumenton
the GPIB, in terms
of interface-function subsets, is identified
in ANSI/IEEE
Std 488-1978. The status of subsets appli-
cable
to 2445 and 2465 Oscilloscopes with Option 10 are
listed in Table 1-1.
A Tektronix standard identifies the format and features
of messages sent over the bus to communicate with other
instruments equipped with a GPIB interface. Specific fea-
tures implemented in the 2445 and 2465 Oscilloscopes are
listed in Table 1-2, and specific formats are shown in Table
1-3.
1-'

Specification
2445/2465 Option 10 Operators
Table 1·1
ANSI/IEEE
Std 488-1978 (GPIB) Functions
Function Description
SH1 Source Handshake. Complete capability.
AH1
Acceptor Handshake. Complete
capability.
T6 Basic Talker. Responds to Serial Poll.
Unaddress
if My Listen Address (MLA) is
received.
L3 Basic Listener. Listen Only. Unaddress if
My Talk Address (MTA) is received.
SR1 Service Request. Complete capability.
RL1 Remote-Local. Complete capability.
DC1 Device Clear. Complete capability.
PPO
Parallel Poll. Does not respond to Parallel
Poll.
DTO Device Trigger. Does not have Device
Trigger capability.
CO Controller. Does not have Controller
capabilities.
NOTE
Open collector bus drivers (Et) are used by this
instrument.
Feature
Indicators
Parameter
Selection
Secondary
Addressing
1-2
Table 1-2
Specific Features Implemented
Description
REM (remote), SRQ (service request). and
LOCK (front-panel lockout) indicators are
included.
Selection is via diagnostic menu and
crt
readout. Nonvolatile storage is in EAROM.
No hard-wired switches are provided for
this feature.
Not implemented.
Table 1-3
Specific Format Choices
Format Parameter Description
Format Characters Not transmitted; ignored on
reception.
Message Terminator Eitherthe End-ar-Identify (EOI)
or the
Line-Feed (LF) mode can be
selected.
Measurement Follows program message-unit
Terminator syntax, which allows numeric
characters
in headers and alphabetic
data arguments
for reporting.
Link Data Used in Usten and Talk modes.
(Arguments)
Instrument Descriptors are added for other
Identification Query installed options.
SETtings Query Extended, using LLSet commands.
to allow block binary response.
IN It Command Causes the oscilloscope
to return to
a power-an condition. All operating
modes then agree with actual front·
panel settings.
Return
to Local (rtf) Asserted when any front-panel
Message control attempts
to change a GPIB·
controllable function.
Time/Date Not implemented.
Commands
Stored Setting Not implemented.
Commands
Waveform Not implemented.
Transmission
Device Trigger (DT) Not implemented.
Multiple Event Not implemented.
Reporting
IEEE 728 Compliance not intended.
PERFORMANCE CONDITIONS
Except as noted in Tables 1-4 and 1-5 of this manual, the
electrical, environmental, and mechanical characteristics
of
Option 10 instruments (including the performance condi-
tions) are identical to those specified in the respective 2445
and 2465 Oscilloscope Operators Manual.

Table 1-4
Option 10 Electrical Characteristics
Performance
Characteristics Requirements
Vertical Position Accuracy Position accuracy is only valid
when:
CH 1, CH 2 {noninverted)
+15°C to +35°C
CH 2 Inverted
-15°C to +55°C
(excluding + 15°C to
+35°C)
CH 3, CH 4
-15°C to +55°C
IEEE 488 Outputs
Volts Out for True
(101 = 48 mAl
Volts Out for False
(IOF = -5.2 mA)
Volts Out with Output
Disabled
Output Leakage
Current with
Power
OFF
(0 V <V
1N
<2.5 V)
IEEE 488 Inputs
Volts
In for True
Volts
in for False
Current in for True
(V
n = 0.5
V)
Current in for False
(V
rr
= 2.7 V)
REV SEP 1984
1. Positioning occurs after a
BALance command is
invoked at the ambient
temperature in which the
instrument is operating.
2. The VOLTS/DIV VAR
control is in the calibrated
detent.
±(0,3 div + 3% of distance
from center screen
in divs +
.5 mVIV/DIV setting.)
Add 0.2 div.
Add 1.5 mV
IV /DIV setting
±(0.7 div + 3% of distance
from center screen in divs.)
Max 0.5 V.
Min 2.5 V.
Max 3.7 V, Min 2.5 V.
Max 40 p.A.
Max 0.8 v, Min 0 V.
Max 5.5 V. Min 2.0 V.
Max -0.1 mAo
Max 20/.l-A.
Specification
2445/2465 Option 10 Operators
Table 1-5
Option 10 Mechanical Characteristics
Characteristics Description
Weight ~ 12.0 kg (26.4 Ib).
With Power Cord,
Cover,
Pouch, Probes.
Operators Manual, and
Options
Domestic Shipping Weight ~ 17.6 kg (38.6Ib).
1-3

Section 2
2445/2465 Option 10 Operators
CONTROLS, CONNECTORS, AND
INDICATORS
FRONT·PANEL CONTROLS
Controls used to sat up the instrument for GPIB opera-
tion (i.e., selecting the instrument's GPIB address. end-of-
message terminator. and talk/listen mode) are described in
Section 3, "GPIB Preparation For Usa". The use of all other
controls for operating the instrun:tent remains the same as
explained in the oscilloscope Operators Manual.
REAR PANEL
See Figure 2-1 forthe location of the following connector.
OPIB CONNECTOR- This connector provides the
IEEE Std 488-1978 compatible electrical and me-
chanical connection to the GPIB.
INDICATORS
See Figure 2-2 for the location of the indicators (LOCK.
SRQ, and REM) added to the front panel above the crt.
®
@
LOCK (Local Lockout)-lIIuminates to indicate that
the Local Lookout universal command has
been
sant over the GPIB. If the instrument has been ad-
dressed and the Remote Enable line asserted, the
front.panel controls, except display and power, will
be locked out.
SRQ (Service Request)-lIIuminates to indicate
that the instrument hasdetected either an error or a
warning condition and is requesting service by the
bus controller.
4633-10
Figure 2-1. Rear Panel GPI8 CONNECTOR.
2-1
... --- .. ----.-.--.----.--.-~-----.--,-------------------------

Controls, Connectors, and Indicators
2445/2465 Option 10 Operators
®
REM (Remote)-lIIuminates to show that the instru-
ment's GPIB interface is in a Remote state. The in-
terface enters a Remote state at the request of the
bus controller. It leaves the Remote state either at
the controller's request or when a GPIB-controUable
front-panel control is changed while the instrument
is not in a Local Lockout state.
READOUT DISPLAYS
Readout displays of GPIB-eontrollabie oscilloscope func-
tions are identical to crt readout displays for non-GPIB-
equipped instruments. Consult Sections 3 and 6 in the
oscilloscope Operators Manual for readout display informa-
tion and typical examples. The additional displays associ-
ated with the operator's GPIB functions are illustrated in
Section 4 of this manual.
2-2
52 ~
51 /
- ..... ron·1X ou,,;u:: 300"''''' G"'.; TAW.
I~ ~ OSOUOSCQPE LOCK. SilO .P;E~
INTENS!TV I!()CUS
((!)c~
4633-04
Figure 2-2. GPIB STATUS indicators.

Section 3
2445/2465 Option 10 Operators
GPIB PREPARATION FOR USE
POWER-UP SEQUENCE
Before initially turning on power to the instrument; read
Section 2, "Preparation for Use", in the oscilloscope Oper-
ators Manual and follow the safety and precautionary in-
formation described there.
The power-up tests, automatically performed each time
the oscilloscope is turned on, examines both
the oscillo-
scope circuitry and the Option 10 GPIB circuitry. Tests spe-
Cifically applicable to Option 10 are integrated into the
power-up tests for the host OSCilloscope and likewise con-
sist of two main parts: Kernel tests and a Confidence test.
Kernel Tests
The Option 10 memory (ROM) is checked by standard
instrument Kernel tests. Kernel test failures will result in
an
~"'- attempt to flash the front-panel A SWP TRIG'D indicator.
,~~ \j,
Even with a Kernel failure, pressing in the NB TRIG
switch may still place the instrument in the normal operating
mode. However,
if the operating mode is successfully en-
tered. instrument operation maybe unpredictable.
NOTE
On some instruments with otheroptions installed, the
AlB TRIG button maybe labeled AlB/MENU.
Confidence Test
Failure of the GPIB Confidence test during power-up is
indicated in the bottom line
of the crt rea(.tout. The failure
display has the following format:
GP TEST 11 FAIL YY
where YY represents the code for the failed test segment.
A Confidence test failure may
not render the GPIB inter-
face inoperable. Pressing in the NB TRIG button may still
place the instrument into the normal operating mode; how-
ever, it may not meet all OPIB specifications.
Successful Power-Up Sequencing
When the power-up routine is successfully completed
without a failure indication, five instrument events occur:
1. The oscilloscope enters the normal operating mode.
2. The GPIB interface enters the Local State (LaCS).
3. The GPIB interface asserts Service Request (SRO).
4. The oscilloscope functions are set to the values which
were established
at least 15 seconds before the in-
strument was last turned off, with front-panel switch
settings taking precedence.
5. The OPIB interface responds to a controller's serial
poll with a statusbyte of 65 (decimal), meaning that all
tests were successful and power is on.
The instrument is
now ready to make measurements as
required.
Unsuccessful Power-Up Sequencing
If power-up tests fail, four instrument events occur:
1. The oscilloscope does not enter the normal operating
mode.
2. The GPIB interface enters the Local State (LaCS).
3. The GPIB interface asserts Service Request (SRO).
4. The GPIB interface responds to a controller's serial
poll with a status byte of 65 (decimal), meaning that
power is on.
As explained in preceding paragraphs,
it may be possi-
ble. after a power-up test failure, to place the instrument
into the normal operating mode by pressing in the
AlB TRIG
switch. If it then functions adequately for your particular
measurement requirement, the instrument can be used, but
refer It to aqualified service technician for repair
of the prob-
lem as soon as possible.
POWER-DOWN SEQUENCE
There are no special sequences aSsociated with
powering down
the instrument. When the POWER switch is
set to OFF, the instrument powers down and SRO is not
asserted.
3·1

Section 4
2445/2465 Option 10 Operators
CONTROLLING OSCILLOSCOPE FUNCTIONS
OVER THE GPIB
INTRODUCTION
This section provides information for controlling the
TEKTRONIX 2445 and 2465 Oscilloscopes via the IEEE Std
488·1978 digital interface. With Option 10 instaUed. all basic
instrument functions (as explained in the oscinoscope Oper-
ators Manual) remain unchanged, Consult the oscilloscope
Operators Manual
to acquire a thorough understanding of
theoperation
of the basic instrument before trying to control
it via the GPIB.
All measurement results returned by GPIB commands
have the same accuracy
as the main instrument or instru-
ment option being accessed by the GPIB interface.
GPIB PARAMETER SELECTION
After power-up sequencing is complete and the oscillo-
scope is in the normal operating mode, selection of GPIB
parameters (primary address, message terminator, and
talk/listen mode) can be made.
Primary Address
The selected GPIB address establishes both the primary
talk and listen addresses for the oscilloscope. It can be set
to any value between 0 and 31, inclusive.
NOTE
Option 10has
no provisions for secondaryaddressing
as defined
by ANSI/IEEE Std488-1978.
With an address of 31, the option still presents an active
load but
does not respond to nor interfere with any bus
traffic. This feature is useful for changing the instrument's
status without turning off
the oscilloscope's power.
Perform the following procedl/re to either set or change
the primary GPIB address:
1. Hold in both the AV and At switches while pushing the
TRIGGER SLOPE switch to access diagnostic mode.
REV JUL 1964
2. Repeatedly push up on the TRIGGER MODE switch
until
GP EXER 11 appears in the bottom line of the crt
readout.
3. Push up on the TRIGGER COUPLING switch to initi-
ate the routine.
4. Rotate the A control until the desired address is dis-
played in the top row of the crt readout; for example:
GPIB ADDRESS 29
NOTE
Trying to select an address outside the range of 0 to
31 will cause LIMIT to appear on the top right side of
the crt display.
5. Push down on the TRIGGER COUPLING switch to
end the routine and update the stored copy of the
address to its new value.
6. Push the NB TRIG switch (or the A/B/MENU switch,
if applicable) to exit diagnostic mode.
Input End-of-Message Terminator and Talk/Listen
Mode
The end·of-message terminator can be selected to be
either the End-or-Identify (EOI) interface signal or the Une-
Feed (LF) character.
When
EOI (normal mode) is selected as the terminator,
the option will:
• Accept only
EOI as the end-of-message terminator.
• Assert EOI concurrently with the last byte of a
message.
When LF is selected
as the terminator, the option will:
• Accept either
LF or EOI as the end-of-message
terminator.
• Send Carriage Retum (CR) followed by LF at the end
of every message, with
EOI asserted concurrently
with the
LF.
4-1

Controlling Oscilloscope Functions Over the GPIB
2445/2465 Option 10 Operators
Two talk/listen modes are selectable:
• TALK LISTEN mode allows the oscilloscope
to both
send and receive data over the GPIB.
• LISTEN ONLY mode permits the oscilloscope to only
receive data over the GPIB.
The default mode is TALK LISTEN.
To select or change the end-at-message terminator and
the talk/listen modes perform the following procedure:
1. Hold in both the t:N and At buttons while pushing the
TRIGGER SLOPE switch to access the diagnostic
mode.
2. Repeatedly push up on the TRIGGER MODE switch
until GP EXER 12 appears in the bottom line of the crt
readout.
3. Push up on the TRIGGER COUPLING switch to initi-
ate the routine.
4. Push the TRIGGER MODE switch up repeatedly until
the desired terminator appears
in the top line of the
crt readout. Push the TRIGGER SOURCE switch up
repeatedly until the desired Talk/Usten mode appears
in the top line of the crt readout. Four
terminator/mode combinations are available:
TERMINATOR EOI MODE TALK LISTEN
or
TERMINATOR LF MODE TALK LISTEN
or
TERMINATOR EOI MODE LISTEN ONLY
or
TERMINATOR LF MOOE LISTEN ONLY
5. Push down on the TRIGGER COUPLING switch to
end the routine and update the stored copy of the
settings.
6. Push the AlB TRIG switch (or the AlB/MENU switch,
if applicable) to exit diagnostic mode.
MESSAGES AND COMMUNICATION
PROTOCOL
The GPIB Option commands can set the instrument op·
erating mode, query the results of measurements made, or
query the state of the oscilloscope. These commands are
4-2
specified in mnemonics that are related to the functions in·
tended to be implemented. For example, the command INlt
initializes instrument settings to states that would exist if
the instrument's power was cycled. To further facilitate pro·
gramming, command mnemonics are similar to front-panel
control names.
Commands
Commands for the 2445 and 2465 Oscilloscopes, like
those for other Tektronix GPIB·controllable instruments, fol·
low the conventions established in a Tektronix Codes and
Formats Standard. The command words were chosen
to be
as understandable as possible, while still allowing a familiar
user
to shorten them as much as necessary, as long as the
result is unambiguous. Syntax is also standardized
to make
the commands eaSier to learn.
In the command lists (Tables 4-2 through 4-7), headers
and arguments are listed in a combination
of uppercase and
lowercase characters. The instrument accepts any abbrevi-
ated header
or argument containing at least the characters
shown in uppercase. Any characters added
to the abbrevi-
ated (uppercase) version must
be those shown in lower-
case. For a query, the question mark must immediately
follow the header. Forexample, any of thefollowing formats
are acceptable:
VMO?
VMOd?
VMOde?
Headers
A command consists of at least a header. Each corn·
mand has a unique header, which may be all that is needed
to invoke a command; e.g.,
NORmal
GO
Arguments
Some commands require the addition of arguments to
the headers to describe e~actly what is to be done. If there
is more to the command than just the header (including the
question mark
if it is a query), then the header must be
followed by at least one space.
In some cases, the argument is either a Single word or a
numeric value; e.g.,
DELay 1.0E-03
HMOde XY

In other cases, the argument itselfrequires another argu-
ment. When a second argument is required, a colon must
separate the two arguments; e.g.,
CH1 VOLts:10
ATRigger MODe:AUTOLevel
Where a header has multiple arguments, the arguments
(or argument pairs, if the argument has its
own argument)
must be separated
by commas; e,g.,
CH1 VOLts:10,COUpling:DC,POSition:1.2
VMOde CH1:OFF,CH2:0N,ADO:ON
Command Separator
It is possible to put multiplecommands intoone message
by separating the individual commands with a semicolon;
e.g.,
CH1 VOLTS:10.COUPLlNG:DCjVMOOE ADD:ON
Message Terminator
As previously explained, messages may be terminated
with either EOI or LF. Some controllers assert
EOI concur-
rently with the last databyte; ot~rs use only the IF charac-
ter as a terminator.
The GPIB interface can be set to accept
either terminator. With EOI selected, the instrument inter-
prets a data byte received with eOI asserted as the end
of
the input message; it also assert$ EOI concurrently With the
last byte of an output message~ With the LF setting. the
instrument interprets the IF char~ter without EOI asserted
{or any data byte received with EOI asserted} as the end of
an input message; it transmits a Carriage Return character
followed by
Una Feed (LF with EOI asserted) to terminate
output messages.
Controlling Oscilloscope Functions Over the GPIB
2445/2465 Option 10 Operators
Command Formatting
Commands sent to the oscilloscope must have the
proper format (syntax) to be understood; however, this for-
mat is flexible in that many variations are acceptable. The
following paragraphs describe this format and the accept-
able variations.
The OSCilloscope expects all commands
to be encoded
as eitheruppercase or lowercase ASCII characters. All data
output is in uppercase.
Spaces, Carriage Returns, and Unefeeds are all format-
ting characters that can be used
to enhance the readability
of command sequences. As a general rule, thesecharacters
can be placed either after commas and semicolons or after
the space
that follows a header.
Numeric Arguments
Table 4-1 depicts the number formats for numeric argu-
ments
in the GPIB command set. As shown in the table,
both signed and unSigned numbers are accepted; but un-
signed numbers are interpreted to be positive.
The symbol
<nrx> indicates that any of the three for-
mats is allowed. When only one specific format is permitted,
it is represented by nr1, nr2, or nr3.
Table 4-1
Numeric Argument Format for GPIS Commands
Numeric Argument Symbol Number Format Examples
.
<nr1>
Integers +1,2, -1, -10
<nn<>
<nr2>
Explicit decimal point -3.2, +5.1, 1.2
<nr3>
Floating point in scientific nota-
tion
+1.E-2, 1.0E+2, 1.E-2, O.02E+3
4-3

Controlling Oscilloscope Functions Over the GPIB
2445/2465 Option 10 Operators
GPIB COMMAND LISTS
Tables 4-2 through 4-7 describe all GPIB commands
available in 2445 and 2465 Oscilloscopes equipped with
only the GPIB Option. The first column lists the name (or
header)
of the command. The capitalized letters must be
present to identify the command, while those shown in low-
ercase are optional. The second column lists arguments that
can be associated with the command. The third column lists
arguments associated with the first argument. Finally. de-
scriptions of each command and its arguments are con-
tained in the last column.
One or more arguments. separated by commas. may be
given in a query to request only the information wanted. For
example,
CH1? COUpling,VARiable
Instrument commands are presented in tables divided
into the following functional groups:
COMMAND TABLE INDEX Page
Vertical Commands .......................... 4-4
Horizontal Commands . . . . . . . . . . . . . . . . . . . . . . .. 4-6
Trigger Commands .......................... 4-7
Delay and Delta Commands ................... 4-9
System Commands .... . . . . . . . . . . . . . . . . . . . . .. 4-10
Calibration and Diagnostic Commands
... . . . . . . .. 4-12
Other 2445 and 2465 options (if installed) use Option 10
for GPIB access. When present, these options add their
own command sets to the GPIB commands listed in Tables
4-2 through 4-7. For information on the additional GPIB
command sets. consult the respective option operators
manual.
Table 4-2
Vertical Commands
Header
Argument Argument Description
CH1 Selects Channel 1 vertical parameters.
COUpling: AC Sets Vertical Coupling to the selected mode.
DC
FIFTY
GND
POSition:
<nrx>
Sets Vertical Position to the value of <nrx> in divisions. Range is
± 10 divisions, with center screen at O.
VARiable:
<nrx>
Sets Vertical Volts/Div Var gain control circuitry to the value of
<nrx>. Values range from 0 to 10 and are not calibrated. Zero
represents the calibrated position.
VOlts:
<nrx>
Sets Vertical Volts/Div gain to the value ot <nrx>. The argument
must be valid for the installed probe.
If the value does not
correspond
to a calibrated position. the next higher calibrated
value will be used and an SRQ warning will be issued.
CH1? Query returns:
CH1 VOLTS: <nr3>, VAR:<nr1>, POS:<nr3>,
COUpling COUPL:string
POSition
VARiable
VOlts
PROBe PROBe must be queried explicitly, e.g., CH1? PROBe. The string
returned for PROBe corresponds
to. the probe attenuation coding
(X1, X10, X100 or X1000).
4-4
--".

r"',
~
\
;;'"
~.
~: "
Header
CH2
CH2?
CH3
CH3?
CH4
CH4?
VMOde
VMOde?
Argument
INVert:
INVert
BWUmit:
CHOp:
CH1:
CH2:
CH3:
CH4:
ADO:
INVert:
CHOp
CH1
CH2
CH3
CH4
ADO
INVert
BWUmit
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
ON
OFF
Argument
Comrolling OscilloScope Functions Over the GPIB
2445/2465 Option 10 Operators
Table 4·2 (cont)
Description
Same as CH1 plus INVert: argument.
Turns Channel 2 inversion on
or off. Default is ON. This command
has the same effect as VMOde INVert:string.
Same as CH1, except query also returns INV:string, where string
is either ON
or OFF.
Same as CH1, except
COUpUng and VARiable arguments are
invalid and POSition range is ± 4 divisions.
Same as CH1. except COUpting and VARiable arguments are
invalid and POSition range is ± 4 divisions.
Selects channels to be displayed, chopped or alternated display
mode. limited or not limited vertical bandwidth, and Channel 2
inversion. When all channels are deselected, Channel 1 is
displayed.
Sets state of the bandwidth limit function. With no arguments.
defaults
to ON.
Selects chopped or alternate display mode. Default is ON.
Turns Channel 1 on or off. Default is ON.
Turns Channel 2 on or off. Default is ON.
Turns Channel 3 on or off. Default is ON.
Turns Channel 4 on
or off. Default is ON.
Turns Channel 1 plus Channel 2 on or off. Default is
ON.
Turns Channel 2 inversion on or off. Default is ON.
Query returns current state of the vertical display: VMO
CH1 :string, CH2:string. CH3:string. CH4:string, ADD:string.
BWL:string. INV:string, CHO:string.
4-5

Controlling Oscilloscope Functions Over the GPIB
2445/2465 Option 10 Operators
Header Argument
HORizontal
ASEcdiv:
BSEcdiv:
MAGnify:
POSition:
TRACEsep:
HORizontal? ASEcdiv
BSEcdiv
MAGnify
POSition
TRACEsep
HMOde
ALTernate
ASWeep
BSWeep
Xy
HMOde?
4-6
Table 4·3
Horizontal Commands
Argument
Description
<nrx>
<nrx>
ON
OFF
<nrx>
Selects Horizontal sweep system parameters.
Selects the A sweep speed
in seconds per division. Range for the
2465 is from 5E-9 to 1.5. For the 2445, range is from 10E-9 to
1.5. Ifthe resulting speed
is faster than the current B sweep, the B
sweep will
be set equal to the A sweep. The effects of MAGnify:
are independent
of ASEcdiv:. See Appendix D for additional
command considerations.
Selects the B sweep speed
in seconds per division. Range for the
2465 is from
5E-9 to 0.15. For the 2445, range is from 10E-9 to
0.15. The sweep speed is updated whether the B sweep is active
or not. If the B sweep requested is slower than the current A
sweep speed, the A sweep will be setequal to the B sweep speed.
The effects of MAGnify: are independent
of BSEcdiv:. See
Appendix 0 for additional command considerations.
Turns the X10 hOrizontal magnification function on
or off. Default
is ON.
Selects the starting position of the sweep. Units are divisions from
the left edge
of the screen and cover a range of approximately ±
5.4 divisions.
Offsets the B sweep from the A sweep by the indicated amount.
Range is from 0
to -4. and units are approximately divisions.
Query returns the current state
of the horizontal selections: HOR
ASE:
<nr3> , BSE: <nr3>. MAG:string. POS: <nr3>,
TRACE:<nr3>;, where the string is either ON or OFF.
Selects Horizontal display mode from the list. Choices are
mutually exclusive.
Selects both normal and delayed sweeps for display. This is
equivalent to pulling the SEC/DIV knob out.
Selects only the A sweep for display.
Selects only the B sweep for display. If both the A and the B
sweeps are set
to the same rate, then a settings conflict SRQ
error is generated.
Selects XY mode.
Query returns: HMO string;, where the string represents one
of
the possible Horizontal display modes.
,~
!